2021 Suburban no rear heat

[Jgreen84]

Have a 2021 Suburban LT the rear climate control is blowing ice cold with controls set to high heat and when synced with the front controls. Anyone else with this issue ?

 

[Chad G 1979]

I have not heard of this issue before in the forum here. Not sure if this might work, but try turning the temp in the rear, all the way to low and let it run for a little bit (30 seconds), then turn the heat all the way to high again. Maybe there is something stuck and that may free up whatever is causing it to blow cold air instead of hot air. Dont know if that would work but worth a shot.

 

[StephenPT]

Double check that you are getting coolant flow back there. With the engine up to temp, feel the two rubber hoses going into the aux heater core. It’s underneath on the rear passenger side. You’ll also see the two AC lines for the aux evaporator.

If that’s good, then look into the blend door actuator - could be stuck and not allowing air to flow across the heater core.

 

[Jgreen84]

Tried that with no luck

 

[Jgreen84]

Double check that you are getting coolant flow back there. With the engine up to temp, feel the two rubber hoses going into the aux heater core. It’s underneath on the rear passenger side. You’ll also see the two AC lines for the aux evaporator.

If that’s good, then look into the blend door actuator - could be stuck and not allowing air to flow across the heater core.

I will check that tomorrow!

 

[Burbs]

Did you figure this out? I have the exact same thing going on with no rear heat in my 2021 Chevy Suburban Premier.

 

[Heavychevy23]

Double check that you are getting coolant flow back there. With the engine up to temp, feel the two rubber hoses going into the aux heater core. It’s underneath on the rear passenger side. You’ll also see the two AC lines for the aux evaporator.

If that’s good, then look into the blend door actuator - could be stuck and not allowing air to flow across the heater core.

What if it’s not getting coolant flow? How do I fix that

 

[MichaelW1012]

Have you solved your issue yet? I just started having the same problem this weekend. Very unhappy with our Tahoe at the moment. Purchased 13 months ago and just had this issue and also had the "Update Failed" issue that supposedly makes the whole infotainment center replaced ($1,500).

 

[reddirtdigger]

I am having the same issue on a 2021 Premier Suburban... no rear heat, but blower putting out lots of air. One of the heater lines into the rear unit is lukewarm, the other cold.... any insight on a rear coolant valve of some type? Does anyone have any insight/references on how to access this area? It appears to be the rear passenger bay side panel in the cargo space, from what I can tell. Any insight would be helpful.

 

[Miami-Dade]

Unfortunately the OP has not been here since last January.

 

[mannyp02]

2021 Yukon Denali XL owner here and I've experienced the same issue throughout ownership (vehicle purchased new). Happens when using remote start (front vents blow hot air, rear vents blow cold like AC) as well as during standard use. Sometimes turning the rear climate off and then on will fix it but generally not. I'm going to ask at my next service but wondering if anyone is aware of a solution?

 

[SavageDad]

2021 Yukon Denali XL owner here and I've experienced the same issue throughout ownership (vehicle purchased new). Happens when using remote start (front vents blow hot air, rear vents blow cold like AC) as well as during standard use. Sometimes turning the rear climate off and then on will fix it but generally not. I'm going to ask at my next service but wondering if anyone is aware of a solution?

Any updates?

 

[WalleyeMikeIII]

Any updates?

Almost sounds like a low coolant issue to me. Do you have enough coolant in the system?

 

[SavageDad]

Almost sounds like a low coolant issue to me. Do you have enough coolant in the system?

Late getting back to this but I topped off my coolant and it still blew cold, a quick WOT romp down the freeway and we're toasty all around.

 

[2024 White Tahoe]

Unfortunately the OP has not been here since last January.

Yes - one of the people that join hoping someone can help them. Often, will not provide an update on the repair or issue.